195
FNCA52 TJSJ 180821
FWFSJU
FIRE WEATHER PLANNING FORECAST FOR PUERTO RICO
NATIONAL WEATHER SERVICE SAN JUAN PR
421 AM AST SUN JAN 18 2026
DISCUSSION
LIKE PREVIOUS DAYS, HIGH DAYTIME RH VALUES ARE EXPECTED TO
PREVAIL. WINDS WILL REMAIN FROM THE EAST TO NORTHEAST TODAY AND
RANGE BETWEEN 12 AND 20 MPH WITH HIGHER GUSTS AROUND 25 MPH AND
SEA BREEZE VARIATIONS. THE RISK IS LOW TODAY, BUT WE ENCOURAGE
PEOPLE TO STAY INFORMED.
PRZ014-190830-
SOUTHEAST COASTAL PLAINS-
421 AM AST SUN JAN 18 2026
TODAY TONIGHT MON
CLOUD COVER MCLEAR MCLEAR MCLEAR
PRECIP TYPE SHOWERS SHOWERS SHOWERS
CHANCE PRECIP (%) 10 10 20
TEMP (24H TREND) 86 (0) 69 (-2) 88
RH % (24H TREND) 52 (0) 89 (-1) 48
WIND 20FT/EARLY(MPH) E 19 G24 E 13 E 17 G23
WIND 20FT/LATE(MPH) E 19 G24 E 13 E 17 G23
MIXING HGT(FT-AGL/MSL)5280 5250
TRANSPORT WND (MPH) E 22 E 18
VENT RATE (KT-FT) 100320 84000
DISPERSION 5 5
DSI 5 4 6
RH RECOVERY EXCELLENT
REMARKS...NONE.
PRZ015-190830-
SOUTHERN HILLS-
421 AM AST SUN JAN 18 2026
TODAY TONIGHT MON
CLOUD COVER MCLEAR MCLEAR MCLEAR
PRECIP TYPE SHOWERS SHOWERS SHOWERS
CHANCE PRECIP (%) 10 10 30
TEMP (24H TREND) 83 (+3) 66 (-3) 84
RH % (24H TREND) 59 (-8) 94 (+4) 59
WIND 20FT/EARLY(MPH) E 14 E 13 E 14
WIND 20FT/LATE(MPH) E 14 E 13 E 14
MIXING HGT(FT-AGL/MSL)5820 5820
TRANSPORT WND (MPH) E 22 E 17
VENT RATE (KT-FT) 110580 87300
DISPERSION 5 5
DSI 5 3 5
RH RECOVERY EXCELLENT
REMARKS...NONE.
PRZ016-190830-
NORTH COASTAL PLAINS-
421 AM AST SUN JAN 18 2026
TODAY TONIGHT MON
CLOUD COVER PCLDY MCLEAR MCLEAR
PRECIP TYPE SHOWERS SHOWERS SHOWERS
CHANCE PRECIP (%) 30 20 30
TEMP (24H TREND) 86 (+1) 69 (-2) 87
RH % (24H TREND) 59 (-7) 97 (+3) 61
WIND 20FT/EARLY(MPH) E 19 E 17 E 20 G23
WIND 20FT/LATE(MPH) E 19 E 17 E 20 G23
MIXING HGT(FT-AGL/MSL)6070 5270
TRANSPORT WND (MPH) E 22 E 20
VENT RATE (KT-FT) 115330 89590
DISPERSION 5 5
DSI 6 5 6
RH RECOVERY EXCELLENT
REMARKS...NONE.
PRZ017-190830-
NORTHERN HILLS-
421 AM AST SUN JAN 18 2026
TODAY TONIGHT MON
CLOUD COVER MCLEAR MCLEAR MCLEAR
PRECIP TYPE SHOWERS SHOWERS SHOWERS
CHANCE PRECIP (%) 30 10 30
TEMP (24H TREND) 85 (+2) 67 (-1) 85
RH % (24H TREND) 57 (-9) 95 (0) 58
WIND 20FT/EARLY(MPH) E 17 E 14 E 18
WIND 20FT/LATE(MPH) E 17 E 14 E 18
MIXING HGT(FT-AGL/MSL)7040 6210
TRANSPORT WND (MPH) E 17 E 15
VENT RATE (KT-FT) 105600 80730
DISPERSION 5 5
DSI 6 3 5
RH RECOVERY EXCELLENT
REMARKS...NONE.
PRZ018-190830-
WEST COAST-
421 AM AST SUN JAN 18 2026
TODAY TONIGHT MON
CLOUD COVER MCLEAR CLEAR MCLEAR
PRECIP TYPE SHOWERS NONE SHOWERS
CHANCE PRECIP (%) 30 0 50
TEMP (24H TREND) 86 (0) 68 (-1) 87
RH % (24H TREND) 58 (-7) 93 (+1) 57
WIND 20FT/EARLY(MPH) E 16 E 13 E 13
WIND 20FT/LATE(MPH) E 16 E 13 E 13
MIXING HGT(FT-AGL/MSL)5040 5160
TRANSPORT WND (MPH) E 15 E 10
VENT RATE (KT-FT) 65520 46440
DISPERSION 5 5
DSI 6 3 5
RH RECOVERY EXCELLENT
REMARKS...NONE.
PRZ019-190830-
EASTERN INTERIOR-
421 AM AST SUN JAN 18 2026
TODAY TONIGHT MON
CLOUD COVER PCLDY MCLEAR PCLDY
PRECIP TYPE SHOWERS SHOWERS SHOWERS
CHANCE PRECIP (%) 30 30 40
TEMP (24H TREND) 84 (+2) 68 (-2) 85
RH % (24H TREND) 62 (-7) 97 (+4) 64
WIND 20FT/EARLY(MPH) E 16 E 16 E 14
WIND 20FT/LATE(MPH) E 16 E 16 E 14
MIXING HGT(FT-AGL/MSL)5720 5680
TRANSPORT WND (MPH) E 23 E 18
VENT RATE (KT-FT) 114400 90880
DISPERSION 5 5
DSI 5 4 5
RH RECOVERY EXCELLENT
REMARKS...NONE.
PRZ022-190830-
LUQUILLO MOUNTAIN RANGE-
421 AM AST SUN JAN 18 2026
TODAY TONIGHT MON
CLOUD COVER PCLDY PCLDY PCLDY
PRECIP TYPE SHOWERS SHOWERS SHOWERS
CHANCE PRECIP (%) 30 40 50
TEMP (24H TREND) 79 (+2) 66 (-3) 79
RH % (24H TREND) 70 (-6) 99 (+4) 71
WIND 20FT/EARLY(MPH) E 14 E 12 E 13
WIND 20FT/LATE(MPH) E 14 E 12 E 13
MIXING HGT(FT-AGL/MSL)5000 4510
TRANSPORT WND (MPH) E 23 E 20
VENT RATE (KT-FT) 100000 76670
DISPERSION 5 5
DSI 6 6 6
RH RECOVERY EXCELLENT
REMARKS...NONE.
PRZ023-190830-
CENTRAL MOUNTAIN RANGE-
421 AM AST SUN JAN 18 2026
TODAY TONIGHT MON
CLOUD COVER MCLEAR MCLEAR MCLEAR
PRECIP TYPE SHOWERS NONE SHOWERS
CHANCE PRECIP (%) 20 0 50
TEMP (24H TREND) 83 (+4) 64 (-2) 84
RH % (24H TREND) 56 (-13) 96 (0) 57
WIND 20FT/EARLY(MPH) E 11 E 9 E 11
WIND 20FT/LATE(MPH) E 11 E 9 E 11
MIXING HGT(FT-AGL/MSL)7390 7100
TRANSPORT WND (MPH) E 15 E 12
VENT RATE (KT-FT) 96070 71000
DISPERSION 5 5
DSI 5 2 5
RH RECOVERY EXCELLENT
REMARKS...NONE.
PRZ024-190830-
CAYEY MOUNTAIN RANGE-
421 AM AST SUN JAN 18 2026
TODAY TONIGHT MON
CLOUD COVER MCLEAR MCLEAR PCLDY
PRECIP TYPE SHOWERS SHOWERS SHOWERS
CHANCE PRECIP (%) 20 20 40
TEMP (24H TREND) 79 (+2) 67 (-1) 80
RH % (24H TREND) 70 (-5) 98 (+2) 71
WIND 20FT/EARLY(MPH) E 13 E 11 E 13
WIND 20FT/LATE(MPH) E 13 E 11 E 13
MIXING HGT(FT-AGL/MSL)5210 5060
TRANSPORT WND (MPH) E 23 E 20
VENT RATE (KT-FT) 104200 86020
DISPERSION 5 5
DSI 6 4 5
RH RECOVERY EXCELLENT
REMARKS...NONE.
PRZ025-190830-
VIEQUES-
421 AM AST SUN JAN 18 2026
TODAY TONIGHT MON
CLOUD COVER PCLDY PCLDY PCLDY
PRECIP TYPE SHOWERS SHOWERS SHOWERS
CHANCE PRECIP (%) 30 40 50
TEMP (24H TREND) 85 (0) 71 (-2) 85
RH % (24H TREND) 59 (-5) 96 (+6) 60
WIND 20FT/EARLY(MPH) E 18 G22 E 19 G23 E 17 G21
WIND 20FT/LATE(MPH) E 18 G22 E 19 G23 E 17 G21
MIXING HGT(FT-AGL/MSL)4150 4150
TRANSPORT WND (MPH) E 26 E 22
VENT RATE (KT-FT) 95450 78850
DISPERSION 5 5
DSI 6 6 6
RH RECOVERY EXCELLENT
REMARKS...NONE.
PRZ026-190830-
CULEBRA-
421 AM AST SUN JAN 18 2026
TODAY TONIGHT MON
CLOUD COVER PCLDY PCLDY PCLDY
PRECIP TYPE SHOWERS SHOWERS SHOWERS
CHANCE PRECIP (%) 40 40 50
TEMP (24H TREND) 85 (+1) 74 (-1) 85
RH % (24H TREND) 62 (-6) 91 (+3) 62
WIND 20FT/EARLY(MPH) E 17 G22 E 19 G23 E 17 G21
WIND 20FT/LATE(MPH) E 17 G22 E 19 G23 E 17 G21
MIXING HGT(FT-AGL/MSL)3960 4110
TRANSPORT WND (MPH) E 26 E 22
VENT RATE (KT-FT) 91080 78090
DISPERSION 5 5
DSI 6 6 6
RH RECOVERY EXCELLENT
REMARKS...NONE.
PRZ027-190830-
SOUTHWEST COASTAL PLAINS AND MONA ISLAND-
421 AM AST SUN JAN 18 2026
TODAY TONIGHT MON
CLOUD COVER CLEAR CLEAR MCLEAR
PRECIP TYPE NONE NONE SHOWERS
CHANCE PRECIP (%) 0 0 20
TEMP (24H TREND) 86 (0) 69 (-2) 89
RH % (24H TREND) 52 (0) 88 (-2) 45
WIND 20FT/EARLY(MPH) E 21 G28 E 19 G24 E 20 G25
WIND 20FT/LATE(MPH) E 21 G28 E 19 G24 E 20 G25
MIXING HGT(FT-AGL/MSL)5250 5210
TRANSPORT WND (MPH) E 25 E 18
VENT RATE (KT-FT) 115500 83360
DISPERSION 5 5
DSI 5 3 5
RH RECOVERY EXCELLENT
REMARKS...NONE.
VIZ001-190830-
SAINT THOMAS AND SAINT JOHN-
421 AM AST SUN JAN 18 2026
TODAY TONIGHT MON
CLOUD COVER PCLDY PCLDY PCLDY
PRECIP TYPE SHOWERS SHOWERS SHOWERS
CHANCE PRECIP (%) 30 30 40
TEMP (24H TREND) 84 (+1) 73 (-2) 85
RH % (24H TREND) 65 (-6) 94 (+5) 62
WIND 20FT/EARLY(MPH) E 18 G23 E 19 G24 E 17 G22
WIND 20FT/LATE(MPH) E 18 G23 E 19 G24 E 17 G22
MIXING HGT(FT-AGL/MSL)3900 3800
TRANSPORT WND (MPH) E 26 E 23
VENT RATE (KT-FT) 89700 76000
DISPERSION 5 5
DSI 6 6 6
RH RECOVERY EXCELLENT
REMARKS...NONE.
VIZ002-190830-
ST CROIX-
421 AM AST SUN JAN 18 2026
TODAY TONIGHT MON
CLOUD COVER PCLDY PCLDY PCLDY
PRECIP TYPE SHOWERS SHOWERS SHOWERS
CHANCE PRECIP (%) 30 30 50
TEMP (24H TREND) 85 (+1) 73 (-1) 86
RH % (24H TREND) 64 (-4) 91 (+4) 62
WIND 20FT/EARLY(MPH) E 18 G23 E 19 G23 E 17 G22
WIND 20FT/LATE(MPH) E 18 G23 E 19 G23 E 17 G22
MIXING HGT(FT-AGL/MSL)4680 4580
TRANSPORT WND (MPH) E 26 E 23
VENT RATE (KT-FT) 107640 91600
DISPERSION 5 5
DSI 6 6 6
RH RECOVERY EXCELLENT
REMARKS...NONE.
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page